package com.cloudeasy.security.core.validate.code.impl;


import com.cloudeasy.security.core.validate.code.*;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.ServletRequestBindingException;
import org.springframework.web.bind.ServletRequestUtils;
import org.springframework.web.context.request.ServletWebRequest;

import java.util.Map;
/**
 * 抽象的图片验证码处理器
 * Create By 郭金宝 on 2019/1/16.<br>
 */
public abstract class AbstractValidateCodeProcessor<C extends ValidateCode> implements ValidateCodeProcessor {

    /**
     * 收集系统中所有的 {@link ValidateCodeGenerator} 接口的实现。
     */
    private final Map<String, ValidateCodeGenerator> validateCodeGenerators;

    private final ValidateCodeRepository validateCodeRepository;

    /**
     * Instantiates a new Abstract validate code processor.
     *
     * @param validateCodeGenerators the validate code generators
     * @param validateCodeRepository the validate code repository
     */
    @Autowired
    public AbstractValidateCodeProcessor(Map<String, ValidateCodeGenerator> validateCodeGenerators, ValidateCodeRepository validateCodeRepository) {
        this.validateCodeGenerators = validateCodeGenerators;
        this.validateCodeRepository = validateCodeRepository;
    }


    /**
     * Create.
     *
     * @param request the request
     *
     * @throws Exception the exception
     */
    @Override
    public void create(ServletWebRequest request) throws Exception {
        C validateCode = generate(request);
        save(request, validateCode);
        send(request, validateCode);
    }

    /**
     * 生成校验码
     */
    @SuppressWarnings("unchecked")
    private C generate(ServletWebRequest request) {
        String type = getValidateCodeType().toString().toLowerCase();
        String generatorName = type + ValidateCodeGenerator.class.getSimpleName();
        ValidateCodeGenerator validateCodeGenerator = validateCodeGenerators.get(generatorName);
        if (validateCodeGenerator == null) {
            throw new ValidateCodeException("验证码生成器" + generatorName + "不存在");
        }
        return (C) validateCodeGenerator.generate(request);
    }

    /**
     * 保存校验码
     */
    private void save(ServletWebRequest request, C validateCode) {
        ValidateCode code = new ValidateCode(validateCode.getCode(), validateCode.getExpireTime());
        validateCodeRepository.save(request, code, getValidateCodeType());
    }

    /**
     * 发送校验码，由子类实现
     *
     * @param request      the request
     * @param validateCode the validate code
     *
     * @throws Exception the exception
     */
    protected abstract void send(ServletWebRequest request, C validateCode) throws Exception;

    /**
     * 根据请求的url获取校验码的类型
     */
    private ValidateCodeType getValidateCodeType() {
        String type = StringUtils.substringBefore(getClass().getSimpleName(), "CodeProcessor");
        return ValidateCodeType.valueOf(type.toUpperCase());
    }

    /**
     * Validate.
     *
     * @param request the request
     */
    @SuppressWarnings("unchecked")
    @Override
    public void validate(ServletWebRequest request) {

        ValidateCodeType codeType = getValidateCodeType();
        this.check(request);
        validateCodeRepository.remove(request, codeType);

    }

    /**
     * Check.
     *
     * @param request the request
     */
    @SuppressWarnings("unchecked")
    @Override
    public void check(ServletWebRequest request) {
        ValidateCodeType codeType = getValidateCodeType();

        C codeInSession = (C) validateCodeRepository.get(request, codeType);

        String codeInRequest;
        try {
            codeInRequest = ServletRequestUtils.getStringParameter(request.getRequest(), codeType.getParamNameOnValidate());
        } catch (ServletRequestBindingException e) {
            throw new ValidateCodeException("获取验证码的值失败");
        }

        if (StringUtils.isBlank(codeInRequest)) {
            throw new ValidateCodeException(codeType + "验证码的值不能为空");
        }

        if (codeInSession == null || codeInSession.isExpired()) {
            validateCodeRepository.remove(request, codeType);
            throw new ValidateCodeException(codeType + "验证码已过期");
        }

        if (!StringUtils.equals(codeInSession.getCode(), codeInRequest)) {
            throw new ValidateCodeException(codeType + "验证码不匹配");
        }
    }
}
